The best way to achieve this is actually to introduce micro turbulence or small particulate in to the stream. This gives the light something to reflect off of and come out to hit your eye. You can add an agent of some kind to the water to make it slightly foggy or you can add small bubbles to the stream. One person put a small air needle at the outlet and used it to inject micro bubbles in the stream which brightened the light effect by a lot.